Rough Idle - with video

[His Dudeness]

That's what mine sounds like and I know that cylinder 3 runs cooler at idle.  5 mins after startup I can still put my palm on 3 whereas 124 are at full temp.  Doesn't affect the running under power but I think the pilot jet on 3 is partially blocked.  It's one of those jobs I've been putting off for the past 2 years.

I think if the jet was blocked it would run leaner and so hotter rather than cooler. If it's cooler it might be a weaker spark. For the bike in the video I'd do the water on the headers trick and get the infra red temp checker as Fazerrider said. Try and get a bit of evidence rather than chasing your own tail.